This text by Hindley and Seldin is a thorough introduction to Alonzo Church's lambda calculus, to Haskell Curry's combinatory logic, and to their interesting interrelationships. Also covers several of the ways that type theories can influence these logics, plus model theories for them. This book is a nice expansion related to a long paper by Felice Cardone and Roger Hindley on the histories of lambda calculus and combinatory logic and their type theories that I read recently, and that good paper influenced me to buy this book. Therefore, I hope to have time to start reading this textbook rather soon.
I did start reading this textbook on Tue 11Oct11, and thru the first 3 short chapters at least, this book is an undergraduate gem! That gets us small exposure to lambda in Chap 1 and to combinatory (CL) in Chap 2, interestingly combining them in Chap 3. Chap 4 is about computable functions in both lambda and CL and mostly contains some definitions and long proofs of several representation theorems. That was a bit tedious.
Most chapters, especially good Chap 5 on undecidability and excellent Chap 6 on formal theories of lambda and CL, are rather short, with Chap 11 at about 40 pages and Chap 13 at about 37 pages being by far the longest. Chapter 7 is about what is called extensionality in lambda, while chapter 8 is about the same for CL. I am not really sure how extensionality is significant, and skipped chapter 8 to successfully read chapter 9 which almost fully combines lambda and CL into one 'thing'.
Chapter 10 is an interesting first look at Church-style type theory for both lambda and CL, and I decided to stop reading this book at end of section 10B and p. 115 on Mon 7Nov11. The type theoretical chapters 10-13 get more intensely difficult, and for me also less interesting. Plus, I am much more interested in lambda than in CL, and so started to feel obligated to skip the CL-related writing in the later chapters.
This is still a very good textbook on its subjects and the one to read if you are truly interested in both lambda calculus and combinatory logic, as those two subjects are treated quite equally in this book.